Article
Geochemistry & Geophysics
J. Xu, G. B. Zhang, H. R. Marschall, J. B. Walters, S. Q. Liu, Z. Lu, L. F. Zhang, H. Hu, N. Li
Summary: The boron geochemistry of white micas and tourmaline in metamorphic rocks provides important insights into fluid-rock interaction and mass transfer processes in subduction zones. The study presents data on boron concentration and isotopic composition of these minerals in an ultra-high pressure metapelitic schist from Xinjiang Province, China. The results indicate the effects of dehydration and rehydration processes during the metamorphic evolution.
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY
(2022)
Article
Geochemistry & Geophysics
Wenbo Li, Xueyuan Qiao, Fanghua Zhang, Lejun Zhang
Summary: Research on tourmalines at the Bilihe porphyry gold deposit in Inner Mongolia, China, identified five types of tourmalines with distinct characteristics and elemental compositions. The tourmalines within different mineralization types exhibit unique features, possibly influenced by fluid composition and rock assimilation.
MINERALIUM DEPOSITA
(2022)
Article
Geochemistry & Geophysics
Zhuang Zhao, Xiaoyong Yang, Qiyao Liu, Youyue Lu, Shanshan Chen, Chao Sun, Zunzun Zhang, Hai Wang, Shuang Li
Summary: The study systematically investigated different types of tourmaline in Shangbao Nb-Ta deposit, identifying the origin, boron source, and Nb-Ta enrichment process based on major, trace elemental and boron isotope analyses. The results revealed that tourmaline precipitated from melt at late magmatic stage, crystallized during magmatic-hydrothermal transition, or originated from hydrothermal fluid, each showing distinct boron sources. High Nb and Ta contents in tourmaline from Shangbao monzogranite suggest its potential as an exploration tool for targeting Nb and Ta mineralization.
Article
Geochemistry & Geophysics
Urmi Ghosh, Dewashish Upadhyay, Kumar Abhinay, Biswajit Mishra
Summary: The study in western India's Proterozoic tungsten belts of Balda and Motiya reveals that the tungsten mineralization process may involve hydrothermal fluid derived from granites rich in Li, Mn, Zn, and Sn, indicating an important role of biotite dissolution and fluid-rock interaction. The chemistry and B-isotope composition of tourmalines suggest that the W-bearing hydrothermal fluid interacted with nearby pelitic rocks during the precipitation of wolframite and tourmaline.
Article
Geosciences, Multidisciplinary
Lukas Krmicek, Milan Novak, Robert B. Trumbull, Jan Cempirek, Stanislav Houzar
Summary: Various metacarbonate and calc-silicate rocks in the Bohemian Massif of the Variscan orogen contain tourmaline in different paragenetic settings, each showing distinctive compositional features. The presence of tourmaline with different B-isotope compositions in specific units suggests regional variations and possible metamorphic processes within the studied areas.
GEOSCIENCE FRONTIERS
(2021)
Article
Geochemistry & Geophysics
Dipak C. Pal, Eileena Das, Ayan Sasmal, Subhadip Adak, Kumar Abhinay
Summary: Hydrothermal iron-oxide-copper-gold (IOCG) deposits are important exploration targets containing multiple economically important metals. Sodium metasomatism is widely found in IOCG provinces, and the formation of albite-rich rocks in these terranes is still debated. This study focuses on the Singhbhum IOCG province in India, which is known for its polymetallic deposits. Through analysis of tourmaline, it is proposed that the albite schist in this province is the product of sodium metasomatism by brines derived from marine evaporites. Similar mechanisms may also be important in the formation of albite-rich rocks in other IOCG provinces.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geosciences, Multidisciplinary
Wenli Sun, Zhidan Zhao, Yaoling Niu, Chunjing Wei, Guochen Dong, Xiaowei Li, Wanming Yuan, Tao Wang, Bingzhang Wang, Tong Pan, Jie Han, Hongliang Cao, Yan Tang, Dicheng Zhu
Summary: The petrogenesis of granitic pegmatite veins in the Chakabeishan Li-Be deposit on the Northern Tibetan Plateau was studied using in-situ major element and B isotope compositions of tourmalines. The results suggest that the pegmatite veins are likely formed through both magmatic and hydrothermal processes, with different generations of tourmalines recording the evolution of the melts and fluids.
GEOSCIENCE FRONTIERS
(2023)
Article
Geochemistry & Geophysics
Peter Bacik, Jana Fridrichova
Summary: Theoretical calculations based on ideal bond valences can predict ion site preference and partitioning in tourmaline structures under low-pressure conditions, determining the range of stable bond lengths and preferences for different ions at specific sites. The final composition of tourmaline is influenced by the interaction of structure with the genetic environment, resulting in structural and environmental constraints that limit the incorporation of certain elements while favoring the abundance of major elements.
AMERICAN MINERALOGIST
(2021)
Article
Geochemistry & Geophysics
Shun Guo, Bin Su, Timm John, Kuidong Zhao, Pan Tang, Yi Chen, Yibing Li
Summary: In the exhumed ultra-high pressure impure marbles from the Dabie terrane, China, the replacement processes of phengitic mica and associated element redistribution were investigated, revealing three microstructures related to boron release. The breakdown of white mica can cause a strong release of boron, significantly influencing the boron budget at convergent plate margins.
Article
Geochemistry & Geophysics
Min Ji, Xiao-Ying Gao, Yi-Xiang Chen, Cong Tu, Guo-Chao Sun, Bing Gong, Xiang -Ping Zha, Yong-Fei Zheng
Summary: This paper presents new results from comprehensive analyses of tourmaline in the Himalayan orogen, providing insights into the influence of dehydration metamorphism and anatectic metamorphism in collisional orogens.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geochemistry & Geophysics
Jia-Wei Xiong, Yi-Xiang Chen, He-Zhi Ma, Hans-Peter Schertl, Yong-Fei Zheng, Kui-Dong Zhao
Summary: A study on metamorphic rocks in the Western Alps reveals evidence of fluid metasomatism during continental subduction, with indication of magmatic origin and potential sourcing from the mantle wedge. This has significant implications for tracing geochemical processes of previous oceanic subduction.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geology
Zhengyu Long, Xiaoyan Yu, Yuyu Zheng
Summary: This study focuses on the petrological and geochemical analysis of tourmaline from the Dayakou emerald deposit to determine the source of ore-forming fluid and emerald genesis. Two types of tourmaline with distinct compositions were identified in this study, suggesting that the deposit is controlled by the fluid-rock interaction between the metamorphic basement and magmatic-hydrothermal fluids. The chemical composition and enrichment of certain elements in tourmaline could be used as exploration indicators for targeting emerald mineralization in the region.
ORE GEOLOGY REVIEWS
(2021)
Article
Geochemistry & Geophysics
Wei Li, Shuyun Cao, Eizo Nakamura, Tsutomu Ota, Zhong Liu, Yanlong Dong, Tak Kunihiro
Summary: Tourmalines in the Laojunshan metamorphic massif exhibit variable structures and compositions, indicating the influence of multi-stage fluid influx and deformation on the formation of tourmalines.
Article
Geochemistry & Geophysics
Matthieu Harlaux, Kalin Kouzmanov, Stefano Gialli, Katharina Marger, Anne-Sophie Bouvier, Lukas P. Baumgartner, Andrea Rielli, Andrea Dini, Alain Chauvet, Miroslav Kalinaj, Lluis Fontbote
Summary: The study on oxygen and boron isotopes in tourmaline from the San Rafael Sn (-Cu) deposit reveals the major fluid processes at the magmatic-hydrothermal transition leading to cassiterite precipitation. Variations in isotopic composition indicate fluid mixing of different sources during different stages, influencing the deposition of cassiterite. This study demonstrates the effectiveness of in situ isotopic analysis in understanding fluid processes in dynamic magmatic-hydrothermal environments.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geochemistry & Geophysics
Michael J. Henehan, Christa D. Klein Gebbinck, Jillian V. B. Wyman, Mathis P. Hain, James W. B. Rae, Barbel Honisch, Gavin L. Foster, Sang-Tae Kim
Summary: Boron isotope ratios in marine calcium carbonate can be used to study marine calcifier physiology and reconstruct past atmospheric CO2 levels. Understanding the pathways of boron incorporation into calcium carbonate is still incomplete, with experimental data suggesting that boron and sodium may substitute in pairs to achieve local charge balance. Interface electrostatics may drive variability in the concentration and isotopic composition of boron in synthetic CaCO3.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Archaeology
Edgar S. Steenstra, Jasper Berndt, Stephan Klemme, Wim van Westrenen, Arlen Heginbotham, Gareth R. Davies
Summary: Excimer nano-second laser ablation inductively coupled plasma mass spectrometry (ns-LA-ICP-MS) is an important tool for chemical characterization of Cu alloys, but variable matrix-induced elemental fractionation poses challenges. This study systematically investigates these issues by analyzing the Cultural Heritage Alloy Reference Material Set (CHARM) of Cu alloy targets, determining the extent to which silicate glass reference materials can be used and the optimal internal standard for a wide range of compositions. By using external standards and internal element standardization, accuracy improvements can be achieved in analyzing brass and bronze artifacts.
Article
Geochemistry & Geophysics
Liam Hoare, Martijn Klaver, Duncan D. Muir, Stephan Klemme, Jane Barling, Ian J. Parkinson, C. Johan Lissenberg, Marc-Alban Millet
Summary: The titanium isotope compositions of different types of rocks, as well as the variations during magmatic differentiation, are discussed in this study. It is found that felsic rocks have heavier titanium isotope compositions compared to mafic rocks, and alkaline magmas have heavier titanium isotope compositions compared to other magma series. The preferential sequestration of light titanium isotopes in Fe-Ti oxides, such as rutile, ilmenite, and titanomagnetite, is suggested as the underlying mechanism for these observations.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Materials Science, Multidisciplinary
Wolfgang Tillmann, Nelson Filipe Lopes Dias, Dominic Stangier, Jasper Berndt, Stephan Klemme, Lukas Kesper, Ulf Berges, Carsten Westphal, Carl Arne Thomann, Jorg Debus
Summary: Modifying amorphous carbon (a-C) with rare-earth elements such as Er and Gd can synthesize functional films with unique characteristics. The addition of Er and Gd reduces the sp(3) content of a-C films and increases the number and size of sp(2)-carbon clusters. The hardness and elastic modulus decrease linearly with increasing Er and Gd contents, while the adhesion is slightly improved.
DIAMOND AND RELATED MATERIALS
(2022)
Article
Geochemistry & Geophysics
A. -S. Bouvier, M. V. Portnyagin, S. Flemetakis, K. Hoernle, S. Klemme, J. Berndt, N. L. Mironov, T. John
Summary: The isotopic composition of Cl can provide insights into element recycling processes in subduction zone settings. Measurements of Cl isotope ratios and trace element concentrations in melt inclusions from samples along the Central American Volcanic Arc reveal restricted ranges of delta Cl-37 values in certain regions and larger variations in others. Combining these measurements with existing knowledge about slab contributions, different endmembers in the subduction zone can be identified.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geology
L. Pasqualetto, F. Nestola, D. E. Jacob, M. G. Pamato, B. Oliveira, S. Perritt, I Chinn, P. Nimis, S. Milani, J. W. Harris
Summary: This study evaluated the reliability of Sm-Nd ages in clinopyroxene inclusions in diamonds. Through crystallographic orientation analyses and Nd diffusion modeling, it was found that some inclusions were co-genetic with diamonds, while others were older. Based on the modeling results, clinopyroxene inclusions smaller than 0.2 mm and equilibrated at temperatures higher than 1050-1080 degrees C may be the most suitable for age determinations.
Article
Multidisciplinary Sciences
Jasper Berndt, Stephan Klemme
Summary: Carbonatites are rare igneous rocks with a global distribution, and their genesis is still a mystery. This study provides evidence that a calcium-rich carbonatite melt found in the Laacher See volcano was formed by liquid immiscibility from a phonolitic magma.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Simon M. Clark, Bruno Colas, Dorrit E. Jacob, Joerg C. Neuefeind, Hsiu-Wen Wang, Katherine L. Page, Alan K. Soper, Philipp Schodder, Patrick Duchstein, Benjamin Apeleo Zubiri, Tadahiro Yokosawa, Vitaliy Pipich, Dirk Zahn, Erdmann Spiecker, Stephan E. Wolf
Summary: Understanding the processes of biomineralization is important for various disciplines, such as quantifying the effects of climate change on marine organisms and advancing biomimetic materials. This study focuses on determining the structure of intermediate amorphous phases, specifically amorphous calcium carbonate (ACC), using simulations and experimental data. The researchers found that ACC consists of ordered nano-domains and a matrix of water molecules, resulting in a gel-like structure. These findings provide a new atomic-scale understanding of ACC and contribute to the general exploration of biomineralization and biomimetic processes.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Paul Pangritz, Christian J. Renggli, Jasper Berndt, Arno Rohrbach, Stephan Klemme
Summary: The evaporation of volatile and moderately volatile elements from silicate glasses is an important research topic in geosciences, environmental, and materials sciences. A new method for synthesizing moderately volatile- and volatile element-bearing boron-aluminosilicate glasses using a two-stage melting process is presented in this study.
ACS EARTH AND SPACE CHEMISTRY
(2022)
Article
Astronomy & Astrophysics
I. P. Baziotis, S. Xydous, A. Papoutsa, J. Hu, C. Ma, L. Ferriere, S. Klemme, J. Berndt, P. D. Asimow
Summary: This study presents a refined view of the mineralogy and texture of the recent fall Vin similar to ales meteorite, revealing multiple shock melt veins and the identification of two high-pressure phases. This suggests that the meteorite has experienced at least one energetic impact.
Article
Chemistry, Physical
Daniel Gaertner, Julia Kundin, Neelamegan Esakkiraja, Jasper Berndt, Adeline Durand, Josua Kottke, Stephan Klemme, Guillaume Laplanche, Gunther Eggeler, Gerhard Wilde, Aloke Paul, Ingo Steinbach, Sergiy V. Divinski
Summary: Diffusion behavior in the CoCrFeMnNi high-entropy alloy is investigated using an augmented tracer/interdiffusion couple approach. A consistent composition-dependent diffusion database is established, and a pair-diffusion model is used to describe the tracer diffusion and chemical concentration profiles. The uphill diffusion of Co observed in the experiment cannot be explained by existing kinetic and thermodynamic databases, and the vacancy wind effect is found to have a strong influence on intrinsic cross diffusion coefficients.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Geosciences, Multidisciplinary
Thomas Gyomlai, Philippe Agard, Horst R. R. Marschall, Laurent Jolivet
Summary: This study uses in-situ Rb/Sr dating on rocks from the Kampos-Lia unit in Syros, Greece to determine the timing of metasomatic events. The main metasomatic event occurred around 36 Ma ago, coinciding with the transition from blueschist to greenschist facies and tectonic exhumation in the Cyclades. The results highlight that fluid-rock interaction along the subduction interface is not continuous, but rather occurs in punctuated, heterogeneously distributed events tied to specific tectonometamorphic episodes.
Article
Chemistry, Multidisciplinary
Simon M. Clark, Vili Grigorova, Bruno Colas, Tamim A. Darwish, Kathleen Wood, Joerg Neuefeind, Dorrit E. Jacob
Summary: Magnesium doped Amorphous Calcium Carbonate can be synthesized by adjusting the Mg/Ca ratio in the precursor solution. The resultant Amorphous Calcium Carbonate crystallizes as aragonite, with no Mg present. Changes in the Mg to Ca ratio have minimal effect on nucleation rates but strongly impact crystal growth rates, suggesting a dissolution-reprecipitation model for aragonite formation via an Amorphous Calcium Carbonate intermediate.
Article
Geosciences, Multidisciplinary
G. Zulauf, J. Linckens, A. Beranoaguirre, A. Gerdes, J. Krahl, H. R. Marschall, L. J. Millonig, N. Neuwirth, R. Petschick, P. Xypolias
Summary: The zircon dating of rocks from the Uppermost Unit of Crete indicates ages of Triassic period, ranging from 237.3 Ma to 242.1 Ma. These rocks, formed in a marine environment, underwent a skarn formation process that lasted for over 20 million years. Based on the results, it is likely that these rocks are derived from the peri-Rhodope domain of the Internal Hellenides or the Pontides of northern Turkey.
INTERNATIONAL JOURNAL OF EARTH SCIENCES
(2023)
Article
Geochemistry & Geophysics
Emmanuel A. Codillo, Veronique Le Roux, Benjamin Klein, Mark D. Behn, Horst R. Marschall, Gray E. Bebout
Summary: Mélange rocks, which are mixtures of subducted materials and serpentinized mantle rocks, may ascend from the slab-top into the overlying mantle and influence the compositional characteristics of arc magmas. This study performed experiments on natural mélange rocks to investigate their melting behavior and buoyancy. The results show that melting of mélange rocks is unlikely to occur along the slab-top, and diapirism into the hotter mantle wedge is required for melting to initiate. The study also evaluates the accuracy of thermodynamic modeling in reproducing the phase equilibria and density evolution of mélange compositions, highlighting the need for an improved thermodynamic database. This research provides experimental constraints on mélange buoyancy and has implications for understanding subduction zone processes.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
E. S. Steenstra, C. J. Renggli, J. Berndt, S. Klemme
Summary: This study experimentally assesses the volatility of volatile elements in magmatic iron meteorites and finds that the presence of sulfur plays a significant role in determining their volatility. The commonly applied 50% condensation temperature models cannot be used for sulfur-bearing Fe liquids and magmatic iron meteorites. The study demonstrates the potential importance of evaporative loss on the elemental depletions in magmatic iron meteorites.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
